Creating a new span for each promQL matcher for each query can end up being too verbose to navigate in grafana. This PR replaces the span with a trace log.
Overall starting a span was also expensive - according to profiles it's about 9% of the CPU of PostingsForMatchers and it's about 25% of the memory allocations. Adding events is about 2% of the CPU and ~5% of the allocations.
In addition to that it removes some log lines in `postingsForMatchersPromise` because I think they just log the same thing multiple times. I also removed some calls to AddEvent to amortize the cost of tracing further.
When out-of-order is enabled, queries go through both Head and OOOHead,
and they both execute the same PostingsForMatchers call, as memSeries
are shared for both.
In some cases these calls can be heavy, and also frequent. We can
deduplicate those calls by using the PostingsForMatchers cache that we
already use for query sharding.
The usage of this cache can skip a newly appended series in the results
for the duration of the ttl.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Fix tests not closing head/block properly
Close Head properly in TestWalRepair_DecodingError
Close Block properly in TestReadIndexFormatV1
Co-authored-by: Christian Simon <simon@swine.de>
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Implement PostingsCloner
PostingsCloner allows obtaining independend clones of a Postings, that
can be used for subsequent calls.
Co-authored-by: Christian Simon <simon@swine.de>
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* IndexReader.PostingsForMatchers() and implement Cache
IndexReader now offers the PostingsForMatchers functionality, which is
provided by PostingsForMatchersCache.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Co-authored-by: Marco Pracucci <marco@pracucci.com>
Co-authored-by: Peter Štibraný <peter.stibrany@grafana.com>
Co-authored-by: Oleg Zaytsev <mail@olegzaytsev.com>
Co-authored-by: Marco Pracucci <marco@pracucci.com>
Co-authored-by: Peter Štibraný <peter.stibrany@grafana.com>
